1. Technical Field
The present invention relates to a computer, and more particularly to an apparatus controlling a cooling fan for a power supply system and a central processing unit in accordance with a power save mode of a power management system.
2. Related Art
As a computer system becomes smaller and more portable, a power save function by which the computer system can be used for a longer time by a battery with a limited capacity has become important. Accordingly, the power save function of a computer is classified into a normal mode, a standby mode, and a suspend mode according to the use of the system and a predetermined time. During the standby mode, a spindle motor of a hard disk driver is interrupted and a monitor screen is turned off, thereby achieving a power saving effect.
Background information regarding computer systems is as follows. Computer systems are information handling systems that are utilized by many individuals and businesses today. A computer system can be defined as a microcomputer that includes a central processing unit (CPU), a volatile memory, a non-volatile memory such as read only memory (ROM), a display monitor, a keyboard, a mouse or other input device such as a trackball, a floppy diskette drive, a compact disc-read only memory (CD-ROM) drive, a modem, a hard disk storage device, and a printer. A computer system's main board, which is a printed circuit board known as a motherboard, is used to electrically connect these components together. A computer system can be a desktop computer, a personal computer, a portable computer such as a notebook computer or palm-sized computer, or other type of computer.
Computer systems include a basic input output system (BIOS) which is an especially important program stored in read only memory. The basic input output system tests a computer every time the computer is powered on. The basic input output system can allocate a computer system's resources automatically, making adjustments needed to accommodate new hardware. Also, the basic input output system governs how system board components interact. When the computer system is powered on, the basic input output system immediately takes control of the computer system and its components. The first duty of the basic input output system is to perform a series of diagnostic routines called the power on self test (POST) routine, which ensures that every part of the computer system's hardware is functioning properly.
I have found that cooling fans in computers use energy and produce noise. This use of energy can be wasteful and production of noise can be unnecessary when a cooling fan is operated even though a central processing unit of a computer system is not in use. Efforts have been made to control a fan in a computer.
Exemplars of recent efforts in the art include U.S. Pat. No. 5,848,282 for Computer System With a Control Function of Rotation Speed of a Cooling Fan For a Microprocessor Chip Therein And a Method of Controlling The Cooling Fan issued to Kang, U.S. Pat. No. 5,881,298 for Portable Computer with Selectively Operable Cooling Unit issued to Cathey, U.S. Pat. No. 5,513,361 for Method and Apparatus for Reducing Power Consumption of a Fan in a Computer System issued to Young, U.S. Pat. No. 5,764,506 for Method and Apparatus for Reducing the Sound Level of a Microcomputer issued to Eynaud, and U.S. Pat. No. 5,687,079 for Method and Apparatus for Improved Control of Computer Cooling Fan Speed issued to Bauer et al.
While these recent efforts provide advantages, I note that they fail to adequately provide an efficient and convenient cooling fan controlling apparatus for a computer.